1. Field of the Invention
The present invention relates generally to plumber's tools. More particularly the invention concerns a waste line cleanout tool adapted for cleaning an removing obstructions from waste lines wherein an elongated member in the form of a coiled spring wire, known as a plumber's snake is advanced through the pipe and rotated.
2. Discussion of the Prior Art
Spring-type plumber's snakes are ordinarily housed in a drum or container having a conoidal wall through which the spring or snake is fed and retracted axially of itself as the container is rotated to cause rotation of the spring. In conventional tools having power-operated spring advancing and retracting means, the feed mechanism typically includes a jaw in the form of a segmented nut, or the like, through which the spring is fed by rotating it so that, in effect, the spring is threaded through the jaw.
Various attempts have been made in the past to design a spring feed device which improves upon this fixed feed nut type arrangement and enables the operator to quickly stop the feed should a blockage be encountered within the pipe so as to avoid kinking of the spring and possible injury to the operator. Among the most successful of these prior art devices are the devices invented by Hunt et al, and described in U.S. Pat. Nos. 2,769,191; 3,224,024 and 3,449,782 and the devices invented by the present inventor and described in U.S. Pat. Nos. 3,882,565; 4,153,966 and 4,395,791. These devices, while clearly superior to similar units on the market, nevertheless lack some versatility in that the feed rollers, which have helically grooved peripheries, cannot be removed from the feed device and cannot be rotated therewithin to enable the automatic withdrawal of the snake from the waste line. Accordingly, with the devices of the aforementioned patents, the motor driving the drum which houses the snake must be reversed in order to change the direction of travel of the snake and withdraw it from the waste line.
Certain types of prior art devices have attempted to feed and withdraw the snake by using cooperating smooth surfaced rollers, the angle of rotation of which can be varied relative to the longitudinal axis of the snake. For example, by placing two or more roller wheels at one angle, a rotating spring can be urged forwardly. By placing the roller wheels at a different angle the spring can be urged rearwardly or in a reverse direction. Exemplary of such devices is that shown in British Patent specification No. 1,198,746.
The smooth roller systems, however, require the exertion of significant downward pressure on the spring by the wheels. The exertion of too much pressure can "bind" the spring and too little pressure can cause undue slippage. Such rollers, therefore, do not perform satisfactorily in cleaning out difficult blockages. On the other hand, where helically grooved rollers are used the exertion of only a minimum amount of pressure on the coiled spring by the rollers will cause uniform feeding the of spring without binding or slippage. Accordingly, the helically grooved rollers perform in a superior fashion to clean out even the most difficult of blockages.
For the aforementioned reasons it is apparent that for some cleanout opertions it is advantageous to use the smooth roller type of system, while in other operations it is advantageous to use the grooved helical roller system. Prior to the present system, two separate machines embodying different feed systems were necessary to achieve this maximum efficiency and versatility. However, the present invention corrects this deficiency by providing for the first time a highly novel apparatus which permits the operator to select the roller configuration best suited for the particular cleanout job.
In several instances, other than situations including severe blockages, the advantages offered by interchangeability of roller sets is apparent. For example, when cleaning waste lines extending between several floors of a high-rise structure, many feet of snake may be introduced into downwardly extending waste lines. Due to the extreme weight of the snake, the smooth roller sets cannot impart enough friction on the snake to raise it as it is withdrawn from the waste lines. Accordingly, in such instances, it is highly advantageous to be able to replace one or more of the smooth rollers with helically grooved rollers which are readily capable of lifting the length of snake.
In cleanout situations when the snake encounters little to medium resistance due to blockages, the smooth rollers can effectively be used. Under these conditions the smooth rollers can be angularly adjusted relative to the longitudinal axis of the snake to increase or decrease the rate of forward or reverse feed of the snake. However, should a severe blockage be unexpectedly encountered, one or more of the smooth rollers can be replaced with a helically grooved roller. With the grooved rollers, the spped of 22 feet per minute feed rate is diminished in direct proportion to the degree of resistance encountered and can range from 0 to 22 feet per minute through the cleanout operation. Such automatic feed rate adjustment is not possible using only the smooth rollers.
In situations wherein it is desired to remove a loose object in the line, it is desirable to replace the grooved rollers with the smooth rollers. This is because with the grooved rollers retrieval of the snake and the object captured by the particular head element attached to the end of the snake can be accomplished only by reversing the motor and, therefore, the direction of rotation of the snake. This reversal of rotation of the snake can cause the head element to "unscrew" or otherwise separate from the object to the withdrawn. However, by replacing the grooved rollers with smooth rollers, the snake and the captured object can be withdrawn by merely changing the angle of the rollers without changing the direction of rotation of the snake. Numerous other operational situations make it highly desirable to be able to interchange the rollers between smooth rollers and helically grooved rollers.
Another imortant advantage of the apparatus of the present invention is the ability of the operator to expeditiously remove the snake and drum housing as a unit and replace them with a new drum housing containing the same or a different size snake. Because of the slotted open design of the housing which carries the feed roolers, the snake can be easily removed from the housing without the necessity of removing the complete feed assembly. This feature enables the ready removal of the drum and snake assembly from the cleanout apparatus whenever the snake is damaged or whenever a larger or smaller diameter snake is required for the particular cleanout job.